The Ants of the Baltic Amber. 
95 
Hairs delicate, sparse, erect, present only on the mandibles, 
clypeus and posterior portion of the gaster. 
Color black. 
Described from a single specimen (B 5385) in the Geolog. Inst. 
Koenigsberg Coli. It is in a beautiful state of preservation in clear 
amber, and with the exception of the anterior portion of the head, 
in a very favorable position for study. 
This ant does not seem to be a typical Iridomyrmex, but I know 
of no other genus to which it can be assigned, and it does not seem 
advisable to erect a new one for its accomodation, since none of the 
characters in which it departs from the other species of Iridomyrmex 
is very prominent. From all of the previously enumerated amber 
species it is distinguished by its subrectangular head and the peculiar 
shape of its thorax and petiole. 
Genus Liometopum Mayr. 
Liometopum oligocenicum , sp. nov. 
Worker (Fig. 46). Length 5,2 mm. 
Head, excluding the mandibles, a little longer than broad, broader 
behind than in front, with rounded posterior corners, concave posterior 
and feebly convex, lateral borders. Eyes in front of the middle of 
the head. Ocelli small, but distinct. Mandibles with convex lateral 
borders, somewhat flattened upper surface and 8 — 9-toothed apical 
borders. Clypeus flattened, with the anterior border straight in the 
middle, projecting and slightly swollen on each side. Maxillary palpi 
long, 6-jointed, labial palpi 4-jointed. Antennse rather stout, the tips 
of the scapes reaching nearly to the posterior corners of the head; 
joints 2— 9 of the funiculi as broad as long, first joint fully twice as 
long as broad, second joint somewhat shorter. Thorax rather long, 
with longer and more angular epinotum and more distinct epinotal 
suture than in the recent species of the genus. Petiole as in the recent 
L. apiculatum Mayr, with the node inclined forward and pointed above. 
Gaster moderately large, elliptical and somewhat flattened dorsoven- 
trally. Legs stout. 
Mandibles very coarsely punctate. Body and appendages opaque, 
without distinct sculpture, but apparently very finely punctate or 
shagreened. 
Erect hairs sparse, visible on the head, thorax and gaster. Pubes- 
cence very short, but dense, visible on the legs, antennse and many 
portions of the trunk. 
